my mods are simple, full 3" Megan TBE with resonated test-pipe, K&N drop in & MBC (no flash of any kind). Logging timing with the pocket logger in 3rd and 4th gear I'm seeing timing is being pulled from 3000-6000 RPM with only a peak of 16 or so with any boost setting above 1.2bar. But if I run the MBC on its lightest setting just to eliminate the boost taper I see between 1.1-1.2 bar in fourth gear and my timing will climb steady to a peak of 19-20 degrees by 7k with a very small drop to 5 degrees at my TQ peak.

I'm guessing the cold air mixed with the crappy winter gas here in PA is the cause but I want to see if anyone else noticed the same thing??

 

boost leaks?

 

nope, I'm always checking for leaks... everything is solid up to an indicated 1.5bar on the stock gauge.

 

Well there is your problem, no tuning. Evo's without tuning add fuel and pull timing, that's just what they do in the upper RPMS. Since it can't pull boost, well it'll pull timing.


Get tuned, go see AL or Turbo Trixx or PDT or Sean IV.

 

I have seen it recommended that you should have some fuel tuning mods when running a boost controller. I have a Hallman MBC, and I believe it says right in the manual, do not install unless you are running with some sort of tuning.

 

It shoudln't pull timing if it's rich. We normally run wonderful timing when untuned even at 21psi (1.45 bar). He shouldn't be pulling timing and should see a peak of 19-20* at 7k. Hopefully, he's not referring to the natural lowering of timing at peak torque (3600-3800) and then the natural climb back to 19-20 that occurs after 5k rpm. 6k isn't far enough to do your log...you need to go all the way to 7k.

 

I'm not talking about the drop of timing at peak TQ but total timing at 7k. When I'm under 1.2bar/17psi my timing will "only" drop to 5* or so at peak TQ (3000-4000) and climb steady without any indicated knock to about 18-20* at @ 7k.

The problem is when I try and run 1.2bar or more on 93 or 94 octain. My timing at peak TQ will drop to 1* (sometimes -1* or lower) and total timing up top will only be around 16* at 7k or so.

I have a wideband o2 sensor but its in another car at the moment so I'm only looking at my narrowband voltage from a pocketlogger so I take these reading with a grain of salt. Voltage on the narrowband reads between 88-94 depending on RPM.

 

And you have no tuning device? The stock tune goes quite lean at peak torque, which causes the timing to drop down. when I was just using my S-AFC, that was my primary torque killer. I could add fuel at peak torque, but that would just make the ECU give even less timing despite being in the safely rich range. It's a no win situation with an SAFC, unless you get injectors that allow you to remove fuel at peak torque even while staying below 12.0:1 AFRs. anyway, your description of 0* timing at peak torque and only climbing to 16* by 7k is what I used to see in the middle of summer on the dyno when running anything over 21psi or when running too lean. .88-.90 is quite lean, whereas .92-.94 should be ok as long as the gas isn't bad.

 

Get tuned, problem will go away I promise

 

what you are seeing on the log is just normal. Don't worry. actually that timing numbers are pretty good for the stock map. with more boost, you can get like -4 at the peak tq.
you are knocking if you see like sudden timing pull at the high RPM range. look for the trouble sign after 4000 rpm. I don't think you can knock before 4000 rpm. It doesn't generate enough heat to knock below 4000 unless you are super lean. if numbers are smoothly going up till the redline, you shouldn't be worrying.

 

The .88v-90v reading is happening early in the RPM band < 4,000, it starts to richen up after that point. I added a % or two of fuel to try and bring it up some but like you said that just results in a lower peak timing number at 7k. I have an SAFC, my tune has changes big time since the summer though and I'm just wondering if there is another reason other then the weather. Lately my car has felt extreamly slow.

Example; in the summer I could remove anywhere between 4-10% fuel with the SAFC up top and still have .92v-94v on pump gas, or less then 12.0:1 as read by my WB. Now in the winter time I'm only removing at most 1-2% fuel up top to get the same .92v-.94v reading. Obviously the air is colder/denser in the winter so you need more fuel in the mixture to keep the same A/F ratio but I can't explain the reason for only being able to run 1.2bar w/o pulling timing.

Yes I have seen -4 at the peak TQ before with more boost in the winter time. I was actually going over my logs from the summer and noticed that my timing didn't drop nearly as much at peak TQ as it does now, and I was running 1.3-1.4 bar back then.

 

I think you're just seeing why it's best to have at least a base flash on top of which you use your SAFC. I went through all the same stuff as you with my SAFC before getting flashed, and although I was in control of my tuning, it just wasn't optimal. When I got a fuel pump, it helped me to be able to pull out 2-3% of fuel everywhere, including 3000-4000rpm, which helped with the peak torque problem, but the only real ways to overcome this peak torque phenomenon with an SAFC is to:

1) Install larger injectors, which forces you to pull out a ton of fuel everywhere, thus allowing you to keep the peak torque area below 12.0 while still having good timing advance
2) Race gas, which allows you to run leaner and thus pull fuel at the peak torque range without knocking and while running higher boost
3) Alky injection for the same reason as #2

This is why all those SoCal guys still swear by the SAFC, because they all get 720cc injectors that allow them to pull lots of fuel on the SAFC. I think a $199 base flash that takes care of the peak torque tuning while also removing fuel cut, providing launch control, and a raised rev limiter is a better way to spend your money, though.